<?php

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  exit('No direct script access allowed');
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 5.1.6 or newer
 *
 * @package		CodeIgniter
 * @author		ExpressionEngine Dev Team
 * @copyright	Copyright (c) 2008 - 2011, EllisLab, Inc.
 * @license		http://codeigniter.com/user_guide/license.html
 * @link		http://codeigniter.com
 * @since		Version 1.0
 * @filesource
 */
// ------------------------------------------------------------------------

/**
 * Output Class
 *
 * Responsible for sending final output to browser
 *
 * @package		CodeIgniter
 * @subpackage	Libraries
 * @category	Output
 * @author		ExpressionEngine Dev Team
 * @link		http://codeigniter.com/user_guide/libraries/output.html
 */
class CI_Output {

  /**
   * Current output string
   *
   * @var string
   * @access 	protected
   */
  protected $final_output;

  /**
   * Cache expiration time
   *
   * @var int
   * @access 	protected
   */
  protected $cache_expiration = 0;

  /**
   * List of server headers
   *
   * @var array
   * @access 	protected
   */
  protected $headers = array();

  /**
   * List of mime types
   *
   * @var array
   * @access 	protected
   */
  protected $mime_types = array();

  /**
   * Determines wether profiler is enabled
   *
   * @var book
   * @access 	protected
   */
  protected $enable_profiler = FALSE;

  /**
   * Determines if output compression is enabled
   *
   * @var bool
   * @access 	protected
   */
  protected $_zlib_oc = FALSE;

  /**
   * List of profiler sections
   *
   * @var array
   * @access 	protected
   */
  protected $_profiler_sections = array();

  /**
   * Whether or not to parse variables like {elapsed_time} and {memory_usage}
   *
   * @var bool
   * @access 	protected
   */
  protected $parse_exec_vars = TRUE;

  /**
   * Constructor
   *
   */
  function __construct() {
    $this->_zlib_oc = @ini_get('zlib.output_compression');

    // Get mime types for later
    if (defined('ENVIRONMENT') AND file_exists(APPPATH . 'config/' . ENVIRONMENT . '/mimes.php')) {
      include APPPATH . 'config/' . ENVIRONMENT . '/mimes.php';
    } else {
      include APPPATH . 'config/mimes.php';
    }


    $this->mime_types = $mimes;

    log_message('debug', "Output Class Initialized");
  }

  // --------------------------------------------------------------------

  /**
   * Get Output
   *
   * Returns the current output string
   *
   * @access	public
   * @return	string
   */
  function get_output() {
    return $this->final_output;
  }

  // --------------------------------------------------------------------

  /**
   * Set Output
   *
   * Sets the output string
   *
   * @access	public
   * @param	string
   * @return	void
   */
  function set_output($output) {
    $this->final_output = $output;

    return $this;
  }

  // --------------------------------------------------------------------

  /**
   * Append Output
   *
   * Appends data onto the output string
   *
   * @access	public
   * @param	string
   * @return	void
   */
  function append_output($output) {
    if ($this->final_output == '') {
      $this->final_output = $output;
    } else {
      $this->final_output .= $output;
    }

    return $this;
  }

  // --------------------------------------------------------------------

  /**
   * Set Header
   *
   * Lets you set a server header which will be outputted with the final display.
   *
   * Note:  If a file is cached, headers will not be sent.  We need to figure out
   * how to permit header data to be saved with the cache data...
   *
   * @access	public
   * @param	string
   * @param 	bool
   * @return	void
   */
  function set_header($header, $replace = TRUE) {
    // If zlib.output_compression is enabled it will compress the output,
    // but it will not modify the content-length header to compensate for
    // the reduction, causing the browser to hang waiting for more data.
    // We'll just skip content-length in those cases.

    if ($this->_zlib_oc && strncasecmp($header, 'content-length', 14) == 0) {
      return;
    }

    $this->headers[] = array($header, $replace);

    return $this;
  }

  // --------------------------------------------------------------------

  /**
   * Set Content Type Header
   *
   * @access	public
   * @param	string	extension of the file we're outputting
   * @return	void
   */
  function set_content_type($mime_type) {
    if (strpos($mime_type, '/') === FALSE) {
      $extension = ltrim($mime_type, '.');

      // Is this extension supported?
      if (isset($this->mime_types[$extension])) {
        $mime_type = & $this->mime_types[$extension];

        if (is_array($mime_type)) {
          $mime_type = current($mime_type);
        }
      }
    }

    $header = 'Content-Type: ' . $mime_type;

    $this->headers[] = array($header, TRUE);

    return $this;
  }

  // --------------------------------------------------------------------

  /**
   * Set HTTP Status Header
   * moved to Common procedural functions in 1.7.2
   *
   * @access	public
   * @param	int		the status code
   * @param	string
   * @return	void
   */
  function set_status_header($code = 200, $text = '') {
    set_status_header($code, $text);

    return $this;
  }

  // --------------------------------------------------------------------

  /**
   * Enable/disable Profiler
   *
   * @access	public
   * @param	bool
   * @return	void
   */
  function enable_profiler($val = TRUE) {
    $this->enable_profiler = (is_bool($val)) ? $val : TRUE;

    return $this;
  }

  // --------------------------------------------------------------------

  /**
   * Set Profiler Sections
   *
   * Allows override of default / config settings for Profiler section display
   *
   * @access	public
   * @param	array
   * @return	void
   */
  function set_profiler_sections($sections) {
    foreach ($sections as $section => $enable) {
      $this->_profiler_sections[$section] = ($enable !== FALSE) ? TRUE : FALSE;
    }

    return $this;
  }

  // --------------------------------------------------------------------

  /**
   * Set Cache
   *
   * @access	public
   * @param	integer
   * @return	void
   */
  function cache($time) {
    $this->cache_expiration = (!is_numeric($time)) ? 0 : $time;

    return $this;
  }

  // --------------------------------------------------------------------

  /**
   * Display Output
   *
   * All "view" data is automatically put into this variable by the controller class:
   *
   * $this->final_output
   *
   * This function sends the finalized output data to the browser along
   * with any server headers and profile data.  It also stops the
   * benchmark timer so the page rendering speed and memory usage can be shown.
   *
   * @access	public
   * @param 	string
   * @return	mixed
   */
  function _display($output = '') {
    // Note:  We use globals because we can't use $CI =& get_instance()
    // since this function is sometimes called by the caching mechanism,
    // which happens before the CI super object is available.
    global $BM, $CFG;

    // Grab the super object if we can.
    if (class_exists('CI_Controller')) {
      $CI = & get_instance();
    }

    // --------------------------------------------------------------------
    // Set the output data
    if ($output == '') {
      $output = & $this->final_output;
    }

    // --------------------------------------------------------------------
    // Do we need to write a cache file?  Only if the controller does not have its
    // own _output() method and we are not dealing with a cache file, which we
    // can determine by the existence of the $CI object above
    if ($this->cache_expiration > 0 && isset($CI) && !method_exists($CI, '_output')) {
      $this->_write_cache($output);
    }

    // --------------------------------------------------------------------
    // Parse out the elapsed time and memory usage,
    // then swap the pseudo-variables with the data

    $elapsed = $BM->elapsed_time('total_execution_time_start', 'total_execution_time_end');

    if ($this->parse_exec_vars === TRUE) {
      $memory = (!function_exists('memory_get_usage')) ? '0' : round(memory_get_usage() / 1024 / 1024, 2) . 'MB';

      $output = str_replace('{elapsed_time}', $elapsed, $output);
      $output = str_replace('{memory_usage}', $memory, $output);
    }

    // --------------------------------------------------------------------
    // Is compression requested?
    if ($CFG->item('compress_output') === TRUE && $this->_zlib_oc == FALSE) {
      if (extension_loaded('zlib')) {
        if (isset($_SERVER['HTTP_ACCEPT_ENCODING']) AND strpos($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip') !== FALSE) {
          ob_start('ob_gzhandler');
        }
      }
    }

    // --------------------------------------------------------------------
    // Are there any server headers to send?
    if (count($this->headers) > 0) {
      foreach ($this->headers as $header) {
        @header($header[0], $header[1]);
      }
    }

    // --------------------------------------------------------------------
    // Does the $CI object exist?
    // If not we know we are dealing with a cache file so we'll
    // simply echo out the data and exit.
    if (!isset($CI)) {
      echo $output;
      log_message('debug', "Final output sent to browser");
      log_message('debug', "Total execution time: " . $elapsed);
      return TRUE;
    }

    // --------------------------------------------------------------------
    // Do we need to generate profile data?
    // If so, load the Profile class and run it.
    if ($this->enable_profiler == TRUE) {
      $CI->load->library('profiler');

      if (!empty($this->_profiler_sections)) {
        $CI->profiler->set_sections($this->_profiler_sections);
      }

      // If the output data contains closing </body> and </html> tags
      // we will remove them and add them back after we insert the profile data
      if (preg_match("|</body>.*?</html>|is", $output)) {
        $output = preg_replace("|</body>.*?</html>|is", '', $output);
        $output .= $CI->profiler->run();
        $output .= '</body></html>';
      } else {
        $output .= $CI->profiler->run();
      }
    }

    // --------------------------------------------------------------------
    // Does the controller contain a function named _output()?
    // If so send the output there.  Otherwise, echo it.
    if (method_exists($CI, '_output')) {
      $CI->_output($output);
    } else {
      echo $output;  // Send it to the browser!
    }

    log_message('debug', "Final output sent to browser");
    log_message('debug', "Total execution time: " . $elapsed);
  }

  // --------------------------------------------------------------------

  /**
   * Write a Cache File
   *
   * @access	public
   * @param 	string
   * @return	void
   */
  function _write_cache($output) {
    $CI = & get_instance();
    $path = $CI->config->item('cache_path');

    $cache_path = ($path == '') ? APPPATH . 'cache/' : $path;

    if (!is_dir($cache_path) OR ! is_really_writable($cache_path)) {
      log_message('error', "Unable to write cache file: " . $cache_path);
      return;
    }

    $uri = $CI->config->item('base_url') .
            $CI->config->item('index_page') .
            $CI->uri->uri_string();

    $cache_path .= md5($uri);

    if (!$fp = @fopen($cache_path, FOPEN_WRITE_CREATE_DESTRUCTIVE)) {
      log_message('error', "Unable to write cache file: " . $cache_path);
      return;
    }

    $expire = time() + ($this->cache_expiration * 60);

    if (flock($fp, LOCK_EX)) {
      fwrite($fp, $expire . 'TS--->' . $output);
      flock($fp, LOCK_UN);
    } else {
      log_message('error', "Unable to secure a file lock for file at: " . $cache_path);
      return;
    }
    fclose($fp);
    @chmod($cache_path, FILE_WRITE_MODE);

    log_message('debug', "Cache file written: " . $cache_path);
  }

  // --------------------------------------------------------------------

  /**
   * Update/serve a cached file
   *
   * @access	public
   * @param 	object	config class
   * @param 	object	uri class
   * @return	void
   */
  function _display_cache(&$CFG, &$URI) {
    $cache_path = ($CFG->item('cache_path') == '') ? APPPATH . 'cache/' : $CFG->item('cache_path');

    // Build the file path.  The file name is an MD5 hash of the full URI
    $uri = $CFG->item('base_url') .
            $CFG->item('index_page') .
            $URI->uri_string;

    $filepath = $cache_path . md5($uri);

    if (!@file_exists($filepath)) {
      return FALSE;
    }

    if (!$fp = @fopen($filepath, FOPEN_READ)) {
      return FALSE;
    }

    flock($fp, LOCK_SH);

    $cache = '';
    if (filesize($filepath) > 0) {
      $cache = fread($fp, filesize($filepath));
    }

    flock($fp, LOCK_UN);
    fclose($fp);

    // Strip out the embedded timestamp
    if (!preg_match("/(\d+TS--->)/", $cache, $match)) {
      return FALSE;
    }

    // Has the file expired? If so we'll delete it.
    if (time() >= trim(str_replace('TS--->', '', $match['1']))) {
      if (is_really_writable($cache_path)) {
        @unlink($filepath);
        log_message('debug', "Cache file has expired. File deleted");
        return FALSE;
      }
    }

    // Display the cache
    $this->_display(str_replace($match['0'], '', $cache));
    log_message('debug', "Cache file is current. Sending it to browser.");
    return TRUE;
  }

}

// END Output Class

/* End of file Output.php */
/* Location: ./system/core/Output.php */